Exhibit 99.(D)(5)

                                                                  EXECUTION COPY

                              UNITHOLDER AGREEMENT

         THIS UNITHOLDER AGREEMENT (this "Agreement"), is entered into as of
                                          ---------
October __, 2001, by and among CALWEST INDUSTRIAL PROPERTIES, LLC, a California
limited liability company ("Calwest"), ROOSTER ACQUISITION CORP., a Maryland
                            -------
corporation and wholly-owned subsidiary of Calwest ("Rooster Acquisition
                                                     -------------------
Corp."), CABOT INDUSTRIAL TRUST, a Maryland real estate investment trust
----
("Cabot"), CABOT INDUSTRIAL PROPERTIES, L.P., a Delaware limited partnership
  -----
("Cabot OP") and the holder identified on Schedule 1 hereto (the "Holder").
  --------                                                        ------

         A. The Holder is, as of the date hereof, the record and beneficial
owner of the number of partnership units issued to the limited partners of Cabot
OP evidencing ownership in Cabot (the "LP Units") as set forth on Schedule 1
hereto;

         B. Concurrently herewith, Calwest, Rooster Acquisition Corp., Cabot and
Cabot OP have entered into an Agreement and Plan of Merger, dated as of the date
hereof (the "Merger Agreement"), which provides, among other things, for Rooster
             ----------------
Acquisition Corp. to conduct a tender offer (the "Offer") for all of the issued
                                                  -----
and outstanding common stock of Cabot ("Cabot Common Shares") and the merger
                                        -------------------
(the "Merger") of Rooster Acquisition Corp. with and into Cabot with Cabot
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continuing as the surviving entity; and

         C. As a condition to the willingness of Calwest and Rooster Acquisition
Corp. to enter into the Merger Agreement and incurring the obligations set forth
therein, including the Offer, and as an inducement and in consideration
therefor, Calwest and Rooster Acquisition Corp. have required the Holder to
enter into this Agreement.

         NOW, THEREFORE, in consideration of the foregoing and the mutual
covenants and agreements set forth herein, and intending to be legally bound
hereby, the parties hereto agree as follows:

         Section 1.   Representations and Warranties of the Holder.  The
                      --------------------------------------------
Holder hereby represents and warrants to Calwest and Rooster Acquisition Corp.
as follows:

                  (a) Such Holder is the record and beneficial owner of the LP
Units set forth opposite his, her or its name on Schedule 1 to this Agreement.

                  (b) Such Holder, if an individual, has the legal capacity to
execute and deliver this Agreement and to consummate the transactions
contemplated hereby. Such Holder, if a corporation, partnership or limited
liability company, is an entity duly organized and validly existing under the
laws of the jurisdiction in which it is incorporated, formed or constituted, and
such Holder has all requisite power and authority to execute and deliver this
Agreement and to consummate the transactions contemplated hereby, and has taken
all necessary action to authorize the execution, delivery and performance of
this Agreement.




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                  (c) This Agreement has been duly authorized, executed and
delivered by the Holder and constitutes the legal, valid and binding obligation
of such Holder, enforceable against such Holder in accordance with its terms,
except (i) as limited by applicable bankruptcy, insolvency, reorganization,
moratorium and other laws of general application affecting enforcement of
creditors' rights generally, and (ii) the availability of the remedy of specific
performance or injunctive or other forms of equitable relief may be subject to
equitable defenses and would be subject to the discretion of the court before
which any proceeding therefor may be brought.

                  (d) The execution and delivery of this Agreement does not, and
the consummation of the transactions contemplated hereby and compliance with the
terms hereof will not, conflict with, result in any violation of or default
(with or without notice or lapse of time or both) under, any provision of any
trust agreement, loan or credit agreement, note, bond, mortgage, indenture,
lease or other agreement, instrument, permit, concession, franchise, license,
judgment, order, notice, decree, statute, law, ordinance, rule or regulation
applicable to the Holder or to the Holder's property or assets. No consent,
approval, order or authorization of, or registration, declaration or filing
with, any court, administrative agency or commission or other governmental
authority or instrumentality, domestic or foreign, is required by or with
respect to the Holder in connection with the execution and delivery of this
Agreement or the consummation by the Holder of the transactions contemplated
hereby.

                  (e) At the time the Holder tenders his, her or its Shares (as
defined below) into the Offer, the Shares will be held by the Holder, or by a
nominee or custodian for the benefit of the Holder, free and clear of all liens,
claims, security interests, proxies, voting trusts or agreements, options,
rights, adverse claims, understandings or arrangements, or any other
encumbrances whatsoever on title, transfer, or exercise of any rights of the
Holder in respect of such Shares (collectively, "Encumbrances"), except for any
                                                 ------------
such Encumbrances arising hereunder. As used herein, the term "Shares" means the
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Cabot Common Shares, together with any Cabot Common Shares acquired by the
Holder after the date of this Agreement, whether upon exercise of options to
purchase Cabot Common Shares or otherwise, all as may be adjusted from time to
time pursuant to Section 5 hereof. The Shares, together with the LP Units, are
referred to herein as the "Securities."
                           ----------

         Section 2. Representations and Warranties of Calwest and Rooster
                    -----------------------------------------------------
Acquisition Corp. Each of Calwest and Rooster Acquisition Corp. jointly and
----------------
severally represents and warrants to the Holder as follows:

                  (a) Calwest is a California limited liability company duly
organized and validly existing and in good standing under the laws of the State
of California; and Rooster Acquisition Corp. is a corporation duly organized and
validly existing and is in good standing under the laws of the State of
Maryland. Each of Calwest and Rooster Acquisition Corp. has all requisite power
and authority to execute and deliver this Agreement and to consummate the
transactions contemplated hereby, and has taken all necessary action to
authorize the execution, delivery and performance of this Agreement.




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                  (b) This Agreement has been duly authorized, executed and
delivered by each of Calwest and Rooster Acquisition Corp. and constitutes the
legal, valid and binding obligation of each of Calwest and Rooster Acquisition
Corp., enforceable against each of them in accordance with its terms, except (i)
as limited by applicable bankruptcy, insolvency, reorganization, moratorium and
other laws of general application affecting enforcement of creditors' rights
generally, and (ii) the availability of the remedy of specific performance or
injunctive or other forms of equitable relief may be subject to equitable
defenses and would be subject to the discretion of the court before which any
proceeding therefor may be brought.

                  (c) The execution and delivery of this Agreement does not, and
the consummation of the transactions contemplated hereby and compliance with the
terms hereof will not, conflict with, result in any violation of or default
(with or without notice or lapse of time or both) under, any provision of any
trust agreement, loan or credit agreement, note, bond, mortgage, indenture,
lease or other agreement, instrument, permit, concession, franchise, license,
judgment, order, notice, decree, statute, law, ordinance, rule or regulation
applicable to Calwest or Rooster Acquisition Corp. or to Calwest's or Rooster
Acquisition Corp's property or assets. No consent, approval, order or
authorization of, or registration, declaration or filing with, any court,
administrative agency or commission or other governmental authority or
instrumentality, domestic or foreign, is required by or with respect to Calwest
or Rooster Acquisition Corp. in connection with the execution and delivery of
this Agreement or the consummation by Calwest or Rooster Acquisition Corp. of
the transactions contemplated hereby.

         Section 3. Tender of the Shares.
                    --------------------

                  Immediately prior to and conditional upon Rooster Acquisition
Corp.'s acceptance for payment and payment for, in accordance with the terms and
conditions of the Offer, all Cabot Common Shares duly tendered pursuant to the
Offer and not withdrawn, the Holder shall exchange the LP Units for Cabot Common
Shares, pursuant to the conversion right of the limited partners set forth in
Section 4.2(e)(1) of the Second Amended and Restated Agreement of Limited
Partnership of Cabot OP. Upon such conversion, the Holder shall immediately
tender such Cabot Common Shares into the Offer. In connection with such exchange
of LP Units for Cabot Common Shares made pursuant to this Section 3, Cabot
hereby waives any notice requirements, including but not limited to the notice
requirement set forth in Section 4.2(e)(1) of the Second Amended and Restated
Agreement of Limited Partnership of Cabot OP, relating to such exchange.

         Section 4.   Transfer of the Securities.
                      --------------------------

                  (a) The Holder shall not: (i) transfer, assign, sell,
gift-over, pledge or otherwise dispose of, or consent to any of the foregoing
(each, a "Transfer") with respect to, any or all of the Securities or any right
or interest therein; (ii) enter into any contract, option or other agreement,
arrangement or understanding with respect to any Transfer; (iii) grant any
proxy, power-of-attorney or other authorization or consent with respect to any
of the Securities; (iv) deposit any of the Securities into a voting trust, or
enter into a voting agreement or arrangement with respect to any of the
Securities or (v) take any other action that would in any way restrict,




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limit or interfere with the performance of the Holder's obligations hereunder or
the consummation of the transactions contemplated hereby or by the Merger
Agreement.

                  (b) The Holder agrees to surrender to Cabot OP, or to the
transfer agent for Cabot, certificates evidencing the LP Units, and shall cause
Cabot OP, or the transfer agent for Cabot OP to place the following legend on
any and all certificates evidencing the LP Units:

                  THE PARTNERSHIP UNITS ISSUED TO LIMITED PARTNERS EVIDENCING
                  OWNERSHIP IN CABOT INDUSTRIAL PROPERTIES, L.P. REPRESENTED BY
                  THIS CERTIFICATE ARE SUBJECT TO CERTAIN RESTRICTIONS ON
                  TRANSFER PURSUANT TO THAT CERTAIN UNITHOLDER AGREEMENT, DATED
                  AS OF OCTOBER __, 2001, BY AND AMONG CALWEST INDUSTRIAL
                  PROPERTIES, LLC, ROOSTER ACQUISITION CORP., CABOT INDUSTRIAL
                  TRUST, CABOT INDUSTRIAL PROPERTIES, L.P. AND THE HOLDER
                  HEREOF. ANY TRANSFER OF SUCH PARTNERSHIP UNITS ISSUED TO
                  LIMITED PARTNERS EVIDENCING OWNERSHIP IN CABOT INDUSTRIAL
                  PROPERTIES, L.P. IN VIOLATION OF THE TERMS AND PROVISIONS OF
                  SUCH AGREEMENT SHALL BE NULL AND VOID AND OF NO EFFECT
                  WHATSOEVER.

         Section 5.  Certain Events.
                     --------------

                  In the event of any change in the Securities by reason of a
stock dividend, stock split, split-up, recapitalization, reorganization,
business combination, consolidation, exchange of shares or common units, or any
similar transaction or other change in the capital structure of Cabot or Cabot
OP affecting the Securities or the acquisition of additional shares or common
units, as applicable, of Securities or other securities or rights of Cabot or
Cabot OP by any Holder (whether through the exercise of any options, warrants or
other rights to purchase Securities or otherwise): (a) the number of Securities
owned by the Holder shall be adjusted appropriately and (b) this Agreement and
the obligations hereunder shall attach to any additional shares or units or
other securities or rights of Cabot or Cabot OP issued to or acquired by each of
the Holders.

         Section 6.  Further Assurances.  The Holder shall, upon request of
                     ------------------
Calwest or Rooster Acquisition Corp., execute and deliver any additional
documents and take such further actions as are necessary or desirable to carry
out the provisions hereof.

         Section 7. Termination. This Agreement, and all rights and obligations
                    -----------
of the parties hereunder, shall terminate immediately upon the earlier of (a)
contemporaneously with any termination of the Merger Agreement in accordance
with its terms or (b) the Merger Effective Time; provided, however, that Section
8 shall survive any termination of this Agreement.


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         Section 8.  Expenses.  All fees, costs and expenses incurred in
                     --------
connection with this Agreement and the transactions contemplated hereby shall
be paid by the party incurring such fees, costs and expenses.

         Section 9.  Miscellaneous.
                     -------------

                  (a) Notices. All notices and other communications hereunder
shall be in writing and shall be deemed given if delivered personally,
telecopied (which is confirmed) or sent by a nationally recognized overnight
courier service, such as Federal Express (providing proof of delivery), to the
parties at the following addresses (or at such other address for a party as
shall be specified by like notice):

                  If to the Holder, at the address set forth on the signature
page hereto:

                  If to Calwest or Rooster Acquisition Corp., to:

                  Calwest Industrial Properties, LLC
                  c/o RREEF Real Estate Investment Managers
                  101 California Street, 26th Floor
                  San Francisco, CA  94111
                  Attn:    Warren H. Otto
                  Phone: (415) 781-3300
                  Fax:   (415) 391-9015

                  with a copy to:

                  Orrick, Herrington & Sutcliffe LLP
                  Old Federal Bank Building
                  400 Sansome Street
                  San Francisco, CA  94111-3143
                  Attn:    Richard Vernon Smith, Esq.
                  Phone: (415) 392-1122
                  Fax:   (415) 773-5759


                  if to Cabot, to:

                  Cabot Industrial Trust
                  Two Center Plaza, Suite 200
                  Boston, MA 02108-1906
                  Attn:    Robert E. Patterson
                  Phone:   (617) 723-0900
                  Fax:     (617) 722-8237





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                  with a copy to:

                  Mayer, Brown & Platt
                  190 S. LaSalle Street
                  Chicago, IL  60603
                  Attn:    Edward J. Schneidman, Esq.
                  Phone:   (312) 701-7348
                  Fax:     (312) 701-7711

         (b)      Headings.  The headings contained in this Agreement are for
                  --------
reference purposes only and shall not affect in any way the meaning or
interpretation of this Agreement.

         (c) Counterparts. This Agreement may be executed manually or by
             ------------
facsimile by the parties hereto, in any number of counterparts, each of which
shall be considered one and the same agreement and shall become effective when a
counterpart hereof shall have been signed by each of the parties and delivered
to the other parties.

         (d) Entire Agreement. This Agreement constitutes the entire agreement
             ----------------
among the parties with respect to the subject matter hereof and thereof and
supersedes all other prior agreements and understandings, both written and oral,
among the parties or any of them with respect to the subject matter hereof and
thereof.

         (e) Governing Law. This Agreement shall be governed by and construed in
             -------------
accordance with the laws of the State of Delaware, without giving effect to the
principles of conflicts of law thereof.

         (f) Assignment. Neither this Agreement nor any of the rights, interests
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or obligations hereunder shall be assigned by any of the parties hereto (whether
by operation of law or otherwise) without the prior written consent of the other
parties except that Calwest and Rooster Acquisition Corp. may assign, in their
sole discretion and without the consent of any other party, any or all of their
rights, interests and obligations hereunder to each other or to one or more
direct or indirect wholly owned subsidiaries of Calwest (each, an "Assignee").
                                                                   --------
Any such Assignee may thereafter assign, in its sole discretion and without the
consent of any other party, any or all of its rights, interests and obligations
hereunder to one or more additional Assignees. Subject to the preceding
sentence, this Agreement will be binding upon, inure to the benefit of and be
enforceable by, the parties and their respective successors and assigns, and the
provisions of this Agreement are not intended to confer upon any person other
than the parties hereto any rights or remedies hereunder.

         (g) Severability of Provisions. If any term or provision of this
             --------------------------
Agreement is invalid, illegal or incapable of being enforced by rule of law or
public policy, all other provisions of this Agreement shall nevertheless remain
in full force and effect so long as the economic or legal substance of the
transactions contemplated by this Agreement is not affected in any manner
adverse to any party. Upon such determination that any provision is invalid,
illegal or incapable of being enforced, the parties hereto shall negotiate in
good faith to modify this Agreement so as




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to effect the original intent of the parties as closely as possible in an
acceptable manner to the end that the transactions contemplated hereby are
fulfilled to the extent possible.

         (h) Specific Performance. The parties hereto acknowledge that money
             --------------------
damages would be an inadequate remedy for any breach of this Agreement by any
party hereto, and that the obligations of the parties hereto shall be
enforceable by any party hereto through injunctive or other equitable relief.

         (i) Amendment. No amendment, modification or waiver in respect of this
             ---------
Agreement shall be effective against any party unless it shall be in writing and
signed by such party.

         (j)      Binding Nature.  This Agreement is binding upon and is solely
                  --------------
for the benefit of the parties hereto and their respective successors, legal
representatives and assigns.

         (k)      Defined Terms.  Capitalized terms used herein and not defined
                  --------------
 herein shall the meanings given to them in the Merger Agreement.






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         IN WITNESS WHEREOF, Calwest, Rooster Acquisition Corp., Cabot, Cabot OP
and the Holder have caused this Agreement to be duly executed and delivered as
of the date first written above.

                          CALWEST INDUSTRIAL PROPERTIES, LLC


                          By:
                               ----------------------------------------------

                          Name:
                                 --------------------------------------------

                          Title:
                                  -------------------------------------------



                          ROOSTER ACQUISITION CORP.


                          By:
                               ----------------------------------------------

                          Name:
                                 --------------------------------------------

                          Title:
                                  -------------------------------------------



                          CABOT INDUSTRIAL TRUST

                          By:
                                --------------------------------------------

                          Name:
                                  ------------------------------------------

                          Title:
                                   -----------------------------------------



                          CABOT INDUSTRIAL PROPERTIES, L.P.


                          By:
                                ---------------------------------------------

                          Name:
                                  -------------------------------------------

                          Title:
                                   ------------------------------------------









                          HOLDER

                          By:
                               ---------------------------------------------

                          Name:
                                 -------------------------------------------

                          Title:
                                  ------------------------------------------

                          Address:
                                    ----------------------------------------













                                   Schedule 1
                                   ----------


   --------------------------------     ----------------------------
   Name of Holder                       Number of LP Units
   --------------------------------     ----------------------------
                                     
   --------------------------------     ----------------------------

   --------------------------------     ----------------------------